Abstract: The objectives of the study include the following: 1. To determine the effects of CO2 treatment on leaf litter nutritional quality after inoculation in the waters of Douglas Lake 2. To determine the effects of elevated CO2 treatment on the relative growth rate (RGR) of G. pseudolimnaeus 3. To determine the relative consumption rate (RCR) and approximate digestibility (AD) of G. pseudolimnaeus fed leaves grown in elevated and ambient CO2 concentrations.